1. Field of the Invention
The present invention relates to an imaging system and an imaging method for imaging a transparent document, such as a film, or a sample with a shade.
2. Description of the Related Art
A document reader that reads a transparent document, such as a film, using a transmission light source is known. In addition, as an apparatus having the same function, there is an imaging system that images a sample with a shade (for example, an electrophoretic gel). Such an imaging system is indispensable when identifying and quantifying biomolecules, especially, proteins or nucleic acids by image analysis.
In a known imaging system using such a transmission light source, there is a problem of ambient light caused by diffusion of illumination light, irregular reflection in the apparatus, and the like. For example, JP1997-44636A (JP-H09-44636A) discloses a correction method for eliminating the influence of light leakage from measurement data by covering a part of an imaging device (CCD) with a light shielding plate and subtracting the signal value detected in pixels (correction pixels) in the covered region from the signal value detected in imaging pixels. In addition, JP1998-142053A (JP-H10-142053) discloses a spectral reflectance measurement apparatus in which the spectral reflectance obtained by measuring a color chart is corrected with the use of the flare spread function.